1. Field of the Invention
The present invention relates to a design support system employed for a design operation using a computer, and relates in particular to a design support system for providing information for bi-directional references between design information and geometry data.
2. Related Art
Design support systems that use computers, such as CAD (Computer Aided Design) systems, are widely employed by design staff. Of the CAD systems, there are two-dimensional systems to be used to prepare drawings and three-dimensional systems to be used to design parts and products by preparing three-dimensional shapes in computer created virtual space. The three-dimensional CAD systems used for design produce shapes substantially similar to final products and are especially employed by design operating staff because it is easy to identify the shapes that are to be produced.
In addition, there are CAE (Computer Aided Engineering) systems that are used to support various types of product design related analyses. The CAE systems use analysis methods, such as the finite element method, to analyze strength and vibration. As the use of three-dimensional CAD systems has spread, an environment, where CAE system usage can be implemented by directly employing design models prepared by three-dimensional CAD systems, has been recently produced.
There are also PDM (Product Data Management) systems, to which some attention has been paid, that are concerned with such subjects as the fabrication and management of parts, the filing of documents relating to parts, and the centralization of information. These PDM systems are used to manage a variety of data concerning product development and they enable the centralization of information management, such as the file management of CAD data and document data, and the management of parts information and the processes employed in the product development.
Generally, for a design operation, not only data which is prepared during the design operation, such as shape data, the configuration of parts and other documents, but also background information (design information), which is used as the basis for determining these data, are required. The background information includes not only general data, such as laws and regulations, design references, manuals, defect information and CAE data, but also other information related to the entire design, such as the intent of the designers, the history of the design operation, the link structure background information and the link reference frequency. When the background information is used correctly, the concurrent engineering, the design changes or the preparation of similar designs can be efficiently performed without any defects being encountered.
FIG. 11 is a diagram for explaining the relationship between background information and geometry data. In order to determine the shape of a specific part 201, background information 301 for the part 201 must be examined. In another case, the geometry data for the part 201 may be obtained as specific example background information 301. That is, during the design operation, correlations are tracked bi-directionally between the background information 301 and the geometry data for the part 201. In addition, geometry data prepared for the complete part 201 are not always necessary, and there may be a case wherein, since a target portion may not be identified when the part 201 is displayed in its entirety, portions 202 constituting partial shape elements of the part 201 are designated. Similarly, in another case, instead of all of the background information 301 having to be referred to, only one document element, such as a single document, a single table or a single graphic related to a design reference 302 and an analysis method 303, is to be referred to.
A conventional CAD system can define an attribute, such as a remark, for each shape element, but is not capable of considering how to handle external design information. A PDM system can employ, as subjects, parts structure management and document management relating to parts and the one-dimensional arrangement of information, but is incapable of meeting requirements exceeding those needed for the information management process and does not obtain reference relationships. Although a PDM system can hierarchically manage design information, when reference relationships between classes are required and a search using a file name or a full search must be performed, necessary information tends to be missed.
An example technique for handling the display of a bi-directional reference relationship between digital documents is disclosed in Japanese Unexamined Patent Publication No. Hei 8-129544. In this publication, only the bi-directional relationship of documents is employed as a problem, and a relationship involving a shape model is not handled. Further, although means for accessing upper or lower part geometry data or graphic data, using tables that show the hierarchical structure of parts, are provided in Japanese Unexamined Patent Publication No. Hei 8-314985 and Japanese Examined Patent Publication No. Hei 5-6910, the means described therein are limited, applying only to the hierarchical structures of parts, and it is difficult to flexibly access required information.
To resolve the technical problems described above, the present invention provides information concerning bi-directional reference relationships between design information and geometry data that are required for a design activity. The present invention may also be used to display reference relationships, especially between two types of information, design information and geometry data, by using reference relationship information that can be used to appropriately express these data.